When using a speaker phone, interference, such as feedback, often reduces the quality of communications. To combat feedback and other distortions in the communications, speaker phones may use signal processing techniques to separate valid communications from system noise. In addition, many speaker phones disable the speaker when input is received by the microphone. This prevents the speaker and the microphone of the speaker phone from forming a feedback loop, but often results in choppy conversations.
Signal processing techniques offer an intelligent method for reducing feedback and other system noise. However, signal processing methods increase both the complexity and the cost of a speaker phone. Also, computers are increasingly used as speaker phones, yet computer sound cards controlling input and output typically provide insufficient resources for complex signal processing.